On youtube, there's a series for some cheap good starter decks way under 5k clintz. there are 10 decks. I'm lvl 15 also and have been using the ep1 piranas deck. I played 2 DT's and have gotten in the top 100 both times without really trying. so check them out
there is a gheist deck, piranas, freaks, all-stars, etc. they all are elo friendly. check them out.
I think NM/GHEIST is a weak combination, personally. Both of those bonuses tend to be defensive in nature. You may find yourself having trouble winning the rounds you really need to win. Mix either Nightmare or GHEIST with an attack manip clan or with Vortex, and you're in business.
That aside, my recommendation for your current deck:
-Rei out, Kusuri in
-Ruby out, Maurice in
This makes your deck a lot more versatile, and a lot stronger vs SoA. As it stands now, you would have 3 characters with 5 power and 1 character with 6 power against SoA... Even with the Uppers attack bonus, 5 power isn't much to work with.